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    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 媒体查询+rem实现元素动态大小变化 */
        @media screen and (min-width:350px) {
            html {
                font-size: 400px;
            }
        }

        @media screen and (min-width:900px) {
            html {
                font-size: 200px;
            }
        }

        .top {
            height: 1rem;
            font-size: 0.1rem;
            background-color: pink;
            text-align: center;
            line-height: 1rem;
        }
    </style>
</head>

<body>
    <div class="top">周杰伦</div>
</body>

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